Implantable intravascular blood pumps are typically used in the later stages of heart disease or after trauma to the heart, when the heart itself is too weak or otherwise incapable of creating sufficient blood pressure and blood circulation to satisfy body function.
Various blood pumps are already in use for the purpose of augmenting or replacing the blood pumping action of damaged or diseased hearts. Blood pumps are commonly used in three situations: (1) for acute support during cardio-pulmonary operations; (2) for short-term support while awaiting recovery of the heart from surgery; or (3) as a bridge to keep a patient alive while awaiting heart transplantation. The pumps may be designed to provide at least one of right or left ventricular assist.
Implantable blood pumps comprise miniaturized pumps capable of being percutaneously or surgically introduced into or adjacent to the vascular system of a patient, typically to provide left or right heart support, or even total heart support. Various types of blood pumps include radial flow centrifugal pumps and axial flow pumps. Examples of axial flow heart pumps are disclosed in co-pending, commonly assigned, U.S. Published Application Nos. 20090203957 (the 957 Publication) and 20110311383 (the '383 Publication) and U.S. Pat. No. 8,007,254 (the '254 patent), the entireties of which are hereby incorporated by reference herein as if fully set forth herein.
Axial flow pumps are commonly implanted within a chamber of the heart, such as is disclosed in the '746 Application. This placement of the pump in the particular chamber effectively immerses the pump within the blood to provide direct pumping support to the particular chamber. However, such placement also decreases the volume of the particular chamber which is available for blood capacity.
In an attempt to remedy this issue, there have been attempts to position a portion of a blood pump through a heart valve or vessel connected to one of the chambers of the heart, while maintaining valve structure and/or function, as is illustrated in U.S. Pat. Nos. 4,753,221 and 5,112,349. However, such positioning may result in insufficient pumping and potential leakage around the pump, may cause unintended damage to the heart valve, and may further present difficulties in stabilizing the pump within the anatomy.
While current implantable blood pump placement, within a chamber of the heart, provides numerous benefits to patients in need thereof, alternative placements may provide additional benefits to patients, in addition to potentially making such devices available to an even wider range of patients in need thereof. Additionally, improved methods and devices for placement of a blood pump outside of a chamber of the heart, such as through a valve, are needed to provide a plausible alternative pump placement.